A037229 -id:A037229 - cp's OEIS frontend

A037228 a(n) = phi(n) - pi(n).

1, 0, 0, 0, 1, -1, 2, 0, 2, 0, 5, -1, 6, 0, 2, 2, 9, -1, 10, 0, 4, 2, 13, -1, 11, 3, 9, 3, 18, -2, 19, 5, 9, 5, 13, 1, 24, 6, 12, 4, 27, -1, 28, 6, 10, 8, 31, 1, 27, 5, 17, 9, 36, 2, 24, 8, 20, 12, 41, -1, 42, 12, 18, 14, 30, 2, 47, 13, 25, 5, 50, 4, 51, 15, 19, 15, 39, 3, 56, 10, 32, 18, 59, 1, 41, 19

Offset: 1

N. J. A. Sloane

sign

It is known that a(n) >= 0 for n >= 61.

D. S. Mitrinovic et al., Handbook of Number Theory, Kluwer, p. 11.

Alois P. Heinz, Table of n, a(n) for n = 1..10000 (first 1000 terms from T. D. Noe)

Cf. A000010, A000720, A037171, A037229.

Table[EulerPhi[n]-PrimePi[n],{n,90}] (* Harvey P. Dale, Feb 02 2021 *)

a(n) = eulerphi(n) - primepi(n); \\ Michel Marcus, Aug 08 2019

A168146 Numbers n such that phi(n) > pi(n).

Original entry on oeis.org

1, 5, 7, 9, 11, 13, 15, 16, 17, 19, 21, 22, 23, 25, 26, 27, 28, 29, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85

Offset: 1

Juri-Stepan Gerasimov, Nov 19 2009

nonn

Numbers n such that A000010(n) > A000720(n).

			A000010(a(1)=1)=1>A000720(a(1)=1)=0; A000010(a(2)=5)=4>A000720(a(2)=5)=3.

G. C. Greubel, Table of n, a(n) for n = 1..1000

Cf. A000010, A000720, A037121, A037228, A037229 (complement), A073456.

Select[Range[100],EulerPhi[#]>PrimePi[#]&] (* Harvey P. Dale, Jun 03 2016 *)

A000010(a(n)) > A000720(a(n)).

A000027 \ A037229. - R. J. Mathar, Nov 19 2009

More terms from R. J. Mathar, Nov 19 2009

cp's OEIS Frontend

A037228 a(n) = phi(n) - pi(n).

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